High Current On–Off Ratio Inkjet-Printed Flexible Microelectromechanical System Switch

This article presents a novel design and fabrication process for a flexible microelectromechanical system (MEMS) switch for dc switching applications. This work is advanced by addressing the key device fabrication process steps for fully inkjet-printed MEMS: 1) details of material selection for each layer of the device; 2) detailed fabrication process; and 3) dc analysis of the switch. A completely fabricated MEMS switch consists of the following: 1) anchors as clampers of a cantilever; 2) cantilever as top electrodes; 3) polyvinyl alcohol (PVA) dielectric layer; and 4) transmission lines as bottom electrodes. A polyethylene terephthalate (PET) flexible thermoplastic polymer with 5-mil thickness is used as a substrate, and particle-free silver conductive ink from Electroninks Inc. is used to print the top and bottom electrodes. Morphological and electrical characterizations have been done for different printed layers and for the complete switch. Finally, after dc analysis, it is found that the switch has a low actuation voltage of (0.1–1.0) V with a current on–off ratio of
$6.5\times10$
7 with the highest current of >40 mA. The device also has a turned-on time of
$25~\mu \text{s}$
, a turned-off time of
$10~\mu \text{s}$
, and an entire switching time of
$35~\mu \text{s}$
. Due to the low cost, no leakage current, and high current on–off ratio characteristics of printed MEMS switch, this can be a good alternative for traditional thin-film transistor switches or traditionally high-cost MEMS switches.